Many surgical procedures require the insertion of catheters and/or surgical devices into blood vessels and other internal structures. For example, in the treatment of vascular disease, it is often necessary to insert an instrument, i.e., a catheter, into the blood vessel to perform the treatment procedure. Such treatment procedures often involve piercing a wall of the blood vessel, inserting an introducer sheath into the blood vessel via the opening, and maneuvering the procedural catheter through the introducer sheath to a target location within the blood vessel. Of course in order to complete such a procedure, the sides of the opening in the wall of the blood vessel must be sealed to prevent bleeding while facilitating healing of the wound. At present, this sealing is commonly accomplished by application of direct pressure over the puncture site by a physician or other trained medical professional. Due to the dangers of thrombosis, the substantial reduction of blood flow through the blood vessel due to the application of pressure is undesirable and potentially dangerous to the patient. In addition, the procedure is extremely time consuming; often requiring that pressure be applied for forty-five minutes or more to achieve acceptable sealing.
Other sealing techniques include the application of a biogenic sealing material over the opening to seal the wound. However, proper placement of the sealing material is difficult to achieve and, the plug of sealing material left inside the blood vessel may result in serious health risks to the patient.
As a result, devices have been developed which are inserted through the puncture in order to suture openings created in blood vessels. However, these devices suffer from various drawbacks.
For example, U.S. Pat. No. 5,417,699 to Klein et al. describes a device wherein two needles coupled to a distal end of an insertion shaft are surrounded by an outer sheath during insertion into an internal structure. Once inside the internal structure, the outer sheath is withdrawn and bowed sections of the needles, which had been constrained within the outer sheath against an outward spring bias, deploy away from the insertion shaft. The insertion shaft is then withdrawn drawing the needles through the walls of the internal structure. The arcuate shape of the needles is intended to bring the needles back along a curved path toward the insertion shaft so that the free ends of the needles may be captured on the shaft and the device withdrawn from the body. Thereafter, the distal ends of the needles must be detached from the insertion shaft so that a length of suture extending between distal ends of the two needles may be drawn through the walls of the internal structure to seal the opening.
However, the curved shape of the proximal ends of the needles of this device requires an insertion sheath of increased diameter. Thus, after withdrawal of a treatment catheter from an opening formed in an internal structure, insertion of the increased diameter outer sheath of the device of Klein et al. actually expands the opening in the wall of the internal structure. In addition, the device of Klein et al. employs several slidably mounted concentric shafts and mechanisms for the deployment and capture of the needles which make the device costly to manufacture and cumbersome to operate.